This study examines whether performance of bout-related physical activity (PA) during morning hours is related to greater overall bout-related PA increases within a preoperative PA intervention for bariatric surgery (BS) patients.
Participants with severe obesity (n = 33; mean age = 45.6 ± 9.6 years; BMI = 45.7 ± 7.0 kg/m2) seeking BS were randomized to and completed 6 weeks of preoperative PA counseling (retention = 82.5%). Participants were encouraged to walk daily at a moderate intensity in bouts ≥ 10 minutes during morning hours to overcome time-related obstacles and establish a PA habit. Timing and amount of bout-related moderate-to-vigorous PA (MVPA) was assessed via objective monitor at pre- and postintervention.
Greater proportion of bout-related MVPA performed during morning hours (4:00 AM–12:00 PM) at postintervention was associated with larger total increases in bout-related MVPA minutes/day (β = .40, P = .03). At postintervention, a greater proportion of participants whose longest MVPA bouts occurred during morning hours (n = 11) achieved the public health guideline (ie, ≥150 bout-related MVPA minutes/week) versus those whose longest MVPA bouts occurred during nonmorning hours (n = 19; 63.6% vs. 26.3%, P = .04).
Intervention-related increases in PA tended to be greatest when PA was performed in the morning. Morning exercise may be a viable strategy for promoting habitual PA in inactive BS patients.
Bond, Thomas, Unick, and Webster are with the Dept of Psychiatry and Human Behavior, Alpert Medical School of Brown University/The Miriam Hospital Weight Control and Diabetes Research Center, Providence, RI. Raynor is with the Dept of Nutrition, University Of Tennessee, Knoxville, TN. Ryder and Vithiananthan are with the Dept of Surgery, Alpert Medical School of Brown University/The Miriam Hospital, Providence, RI.